Teachers in Kansas will have to spell out specific objections to Darwin's theory of evolution under a new set of teaching guidelines approved in the midwestern heartland state last night.

In a major success for proponents of "intelligent design" and other creationist theories of evolution, the Republican-dominated Kansas Board of Education ruled by six votes to four that, from 2008, teachers will have to give reasons why Darwinism is just one of many theories to explain the origins of life.

Until yesterday, Kansas had allowed teachers to take issue with the theory of evolution. Now they will be forced to do so, using an official list of perceived weaknesses in Darwin's theory.

Kansas has a history of defying evolution. Notoriously, in 1999, the state deleted most references to evolution in the science standards, a decision that was substantially reversed in 2001.

Critics of the new science standards say that that all the objections listed in them derive from "intelligent design" (known as "ID"), a theory that maintains that the life is irreducibly complex and must have been created by a higher power.

"All the arguments inserted in the standards are only found in the literature of intelligent design," said Jack Krebs, a high school maths teacher and vice president of Kansas Citizens for Science, which opposes the change. "Teaching the criticisms is teaching ID."

Eugenie Scott, director of the National Center for Science Education, said that the tactic used by the creationist lobby in Kansas - to portray criticism of evolution as part of encouraging diversity of thought - is likely to imitated in other parts of America. In August, President Bush endorsed teaching intelligent design alongside evolution.

"This action is likely to be the playbook for creationism for the next several years," said Mr Scott. "We can predict this fight happening elsewhere."

But supporters of the new regulations say they will lead to open discussions. "We are being very brave. We are brave enough to have all areas discussed," said Kathy Martin, a Republican member of the school board who voted for the change. "Students will be informed and not indoctrinated."

The Discovery Institute, a conservative think tank, said that the new science standards in Kansas will led to a fuller understanding of evolution. "Under these standards students will learn more about evolution not less as some Darwinists have falsely claimed," said a spokesman for the institute.

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